Conventional electrochemical energy storage systems, such as lithium-ion batteries, frequently use graphite, which is characterized by a good Coloumb efficiency and a low charge loss in a first charging cycle, as anode material. With regard to the requirements for future energy storage systems, in particular in the area of electromobility, the use of anode materials having greater storage capacity is important. Silicon has these desired properties, but on the other hand it has lower cycle stability than graphite. It is known that this effect may be counteracted for lithiating the anode material.
U.S. Pat. No. 5,543,021 A provides a method for producing prelithiated carbon-containing anode materials and their use in electrodes for energy storage systems. Butyllithium and lithium naphthalide are used as lithiation reagents. The by-products that result during the lithiation are present as a gas or solid, and may therefore be problematic later in the process.
U.S. Pat. No. 7,776,473 B2 provides a silicon and silicon oxide composite that is doped with lithium. The composite is produced by reacting silicon oxide with metallic lithium. The slow diffusion of the solid lithium into the silicon oxide represents the rate-determining step of this reaction.
WO 2015/127290 A1 describes the surface modification of silicon-containing nanoparticles, using lithium-compounds, and the use of the modified nanoparticles as anode material in lithium-ion batteries.